1. Field of the Invention
The present invention relates to a method, apparatus, and computer program for configuring networks. More particularly, the present invention relates to a network configuration method, apparatus, and program stored in a computer-readable medium for configuring networks to maintain the quality of services executed between an access source location and an access destination location.
2. Description of the Related Art
Many businesses have used reliable, bandwidth-guaranteed network services to interconnect their business locations over wide area networks (WAN) based on public switched telephone networks (PSTN), public data communications networks, or leased lines. The communications technologies used in this type of WANs include the Point-to-Point Protocol (PPP), High Level Data Link Control (HDLC), Integrated Services Digital Network (ISDN), Frame Relay, and Asynchronous Transfer Mode (ATM). The recent trend, however, is toward virtual private networks using Internet Protocol (IP-VPN) or wide area Ethernet™ services. While IP-based services generally offer no guarantee of bandwidth and are relatively less reliable, the enterprise network users can enjoy a greatly increased bandwidth of, for example, more than 1 Gbps, in contrast to some 100 Mbps of conventional networks.
Also, recent years have seen a widespread use of IP phones based on the Voice over IP (VoIP) technologies, as well as a proliferation of video conference systems using streaming techniques. Network systems tend to carry those new service traffic in addition to business applications. IP phones and video conference systems are more sensitive to network delays than other ordinary data communication services. A delay due to an excessive burst of traffic would degrade the quality of a delivered sound or video stream.
Some legacy applications (i.e., non-web-based applications) providing mission-critical services 24 hours, 365 days a year are designed on the assumption that they can use network connections with a guaranteed bandwidth. Those applications cannot migrate to a new web-based environment unless the network system offers guaranteed bandwidth services. To meet such demands, IP-based wide-area networks are required to provide bandwidth-guaranteed, secure and reliable communication channels equivalent to conventional leased line connections.
Under the above-described circumstances, more and more functions are integrated into a network device (e.g., router and switch) deployed at business locations and at the edge of a WAN. For example, recent network devices have the functions of controlling bandwidth, priority, security, and routing with multihoming support. Those features are also available as dedicated appliances that can work seamlessly in combination with a router or a switch.
To realize a highly reliable IP-based WAN by using such edge devices, some verification mechanism has to be implemented to quickly check the configuration of many edge devices distributed across the network. This may typically be realized by using Telnet login and command line interface (CLI) of each edge device (e.g., routers, switches, traffic controller, security controllers) located at offices or on WAN edges. It is, however, not easy to check the order and consistency of device settings, while keeping in mind the difference between vender-specific CLI specifications, as well as considering the overall network topology. This difficulty leads to an increased cost of network system operations.
One known method to reduce the workload of operations and management is to distribute a configuration file from an operation management site to each edge device on the network. This method, however, merely automates the task of applying the settings that are previously prepared. One drawback of the method is its dependency on the interface specifications of each individual device and the consequent lack of versatility. Another drawback is that the method does nothing about guaranteeing bandwidth for multiple services. Yet another drawback is that the operator needs to know well about quality of service (QoS) control mechanisms.
To address the problems described above, Japanese Patent No. 3137583 proposes a static setting method for routing parameters of network devices. However, the proposed method still lacks consideration of bandwidth guarantee for multiple services.